1. Field of the invention
The present invention is generally concerned with fitting a holding part onto an eyeglass lens to be worked on, for example trimmed, the holding part being adapted to adhere to the lens temporarily, by means of a sucker, for example, to enable the lens to be fitted to and locked in position on a machine for carrying out the work.
2. Description of the prior art
Devices for fastening a holding part on an eyeglass lens form part of centering devices, for example, used before the work is carried out to define either the geometrical center of the eyeglass lens to be worked on or its optical center, the holding part having then to be fitted at a specific location relative to one or the other of these centers.
In practise they comprise an arm which is adapted to receive removably the holding part to be fitted to the eyeglass lens and a carriage on which the arm pivots between two end positions, namely a loading and offloading position and a fitting position. Carried by a frame, the carriage is mobile between two end positions on the frame, namely a rest position and an end of travel position, during which movement the arm is moved into alignment in the fitting position with a plate on which the eyeglass lens is placed beforehand.
This is the case, for example, in American Pat. No 4,543,752.
According to this American patent the carriage carrying the arm can be moved manually or by a motor.
In either case the arm pivots in the same direction as the carriage moves, with a screw-and-nut type coupling between it and the carriage.
This type of coupling inevitably produces significant friction, compromising efficiency.
A general object of the present invention is an arrangement which is advantageously free of this disadvantage and is also suitable for manual or motorized operation.